MC68HC705P9 Datasheet, PDF (136/160 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Freescale Semiconductor, Inc.
Analog-to-Digital Converter (ADC)
To prevent excess power dissipation, do not use an ADC pin as an
analog input and a digital input at the same time.
Using one of the port pins as the ADC input does not affect the ability to
use the remaining port pins as digital inputs.
Reading a port pin that is selected as an analog input returns a logic
zero.
11.7.2 ADC Data Register
The ADC data register (ADDR) is a read-only register that contains the
result of the most recent analog-to-digital conversion.
$001D Bit 7
6
5
4
3
2
1
Bit 0
Read: Bit 7
6
5
4
3
2
1
Bit 0
Write:
Reset:
Unaffected by reset
Figure 11-4. ADC Data Register (ADDR)
11.8 Low-Power Modes
11.8.1 Stop Mode
The STOP instruction turns off the ADC and aborts any current and
pending conversions.
11.8.2 Wait Mode
The ADC continues to operate normally after the WAIT instruction. To
reduce power consumption in wait mode:
• If the ADC is not being used, clear both the ADON and ADRC bits
before entering wait mode.
• If the ADC is being used and the internal clock rate is above
1 MHz, clear the ADRC bit before entering wait mode.
Technical Data
136
Analog-to-Digital Converter (ADC)
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MC68HC705P9 — Rev. 4.0
MOTOROLA